1. Field of the Invention
This invention relates to an operation method of a recipe control process designed to control film deposition on semiconductor wafers, among others, and also to a method to correct the recipe for each processing target such as wafer.
2. Description of the Related Art
Embodiment of continuous film deposition on the wafers to be produced on a sheet-feed type semiconductor manufacturing system requires that film be deposited on a specified number of wafers in a reactor chamber through a control like the one shown in FIGS. 8 and 9, after which a cleaning process be performed in which specific gas is introduced to clean the reactor chamber. First, a system recipe is started (S1). Then, the system is initialized and initial values are set (S2). Initial values include cleaning counter and lot counter settings, the number of wafers to be processed before a cleaning process is performed, and the number of wafers to be processed per lot (total number of wafers to be set). Next, a wafer film deposition subroutine is called and film deposition is started (S3). This wafer film deposition subroutine is controlled by a process recipe. As shown in FIG. 9, once the wafer film deposition process is started (S110) the recipe settings that have been input in advance are loaded (S120). Recipe control is performed in accordance with these settings (S140) until film deposition on the wafer is completed (S150).
After completion of film deposition on one wafer, the cleaning counter is incremented by one, along with the lot counter that is also incremented by one (S4). Next, the lot counter is checked to determine whether or not the number of wafers to be processed per lot, as set in step S2, has been reached. If the specified number is not yet reached, then the cleaning counter is checked to determine whether or not the number of wafers to be processed before cleaning, as set in step S2, has been reached (S6). If the specified number is not yet reached, the processing flow returns to the wafer film deposition process (S3). If the specified number has already been reached, the cleaning process is started, after which the cleaning counter is reset to zero (S7) and the processing flow returns to the wafer film deposition process (S3). If the specified number of wafers to be processed per lot has already been reached in step S5, whether or not the cleaning counter is zero is then determined (S8). If the cleaning counter is not zero, the cleaning process is performed, after which the cleaning counter is reset to zero (S9) and the system operation ends (S10). If the cleaning counter is zero in step S8, the system operation ends immediately (S10).
FIG. 10 is an example of the system recipe operation screen. In this example, RC1 (reactor chamber 1) is selected among the tabs (100), in order to process in this reactor chamber the wafers stored under respective slot numbers (S1) (102) corresponding to the slots in the cassette. The execution sequence is specified as shown in the wafer execution sequence (Ex) field (101). In this example, the wafer in slot 9 is executed first, followed by those in slot 3, slot 2, and so on. Various patterns can be specified for executing the stored wafers, in addition to the ascending order or descending order of slot numbers. In the Process Name field (103), a desired process recipe to be executed in the reactor chamber is specified for each wafer. It is also possible to specify a wafer transfer pattern in each process recipe.
FIG. 11 is an example of the operation screen for a process recipe specified in the Process Name field (103) in FIG. 10 (the gas type field is intentionally left blank). In a process recipe, various control elements that define wafer processing, such as pressure, temperature and gas flow rate, can be set. The time of each step can also be set in the Step Time field (110). For example, the film deposition (DEPO) step is set to 10 seconds.
As explained above, the purpose of the recipe control operation is to package all relevant conditions and specify applicable conditions for each slot in advance. As shown in FIG. 9, once the film deposition process is started for the wafers in the specified slots, the recipe settings that have been input in advance are loaded and recipe control is performed in accordance with these settings. Since a process recipe is already specified for each of the predefined slots, however, changes occurring in the condition inside the reactor chamber cannot be reflected to change the processing accordingly.